Field of the Invention
One or more embodiments of the invention are related to the field of virtual reality systems. More particularly, but not by way of limitation, one or more embodiments of the invention enable a virtual reality display system that renders different regions of a display at different resolutions as well as tracks movements of a user and quickly renders a virtual reality display based on those movements.
Description of the Related Art
Virtual reality systems are known in the art. Such systems generate a virtual world for a user that responds to the user's movements. Examples include various types of virtual reality headsets and goggles worn by a user, as well as specialized rooms with multiple displays. Virtual reality systems typically include sensors that track a user's head, eyes, or other body parts, and that modify the virtual world according to the user's movements. The virtual world consists of a three-dimensional model, computer-generated or captured from real-world scenes. Images of the three-dimensional model are generated based on the user's position and orientation. Generation of these images requires rendering of the three-dimensional model onto one or more two-dimensional displays. Rendering techniques are known in the art and are often used for example in 3D graphics systems or computer-based games, as well as in virtual reality systems.
A major challenge for existing virtual reality systems is combining realistic images with low-latency rendering, so that user's virtual reality experience matches the rapid feedback to movement observed in real environments. Existing systems often have long latency to measure changes in the user's position and orientation, and to rerender the virtual world based on these changes. 3D rendering is a complex and processor intensive operation that can take potentially hundreds of milliseconds. The result is that users perceive noticeable lag between their movements and the rendering of updated virtual environments on their displays. Three technology trends are compounding this challenge: (1) The complexity of 3D models is growing as more 3D data is captured and generated. (2) Resolution of virtual reality displays is increasing, requiring more computational power to render images. (3) Users are relying increasingly on mobile devices with limited processor capacity. As a result of these trends, high latency in rendering virtual reality displays has become a major factor limiting adoption and applications of virtual reality technology. There are no known systems that provide sufficiently low-latency rendering and display to generate highly responsive virtual reality environments given these technology constraints.
One factor contributing to rendering latency is the resolution of a virtual reality display. In general, displays with large numbers of pixels require more rendering computation and thus may experience greater latency. Displays known in the art typically consist of rectangular arrays of pixels with uniform pixel density throughout the display. However, human vision has high resolution only in the center of the field view. Therefore, rendering images at high resolution on the sides of a display may be unnecessary, and may contribute to higher latency without improving the user's experience.
For at least the limitations described above there is a need for a variable resolution virtual reality display system.